title: Effects of inspiratory muscle training in cystic fibrosis: a systematic review.
abstract: OBJECTIVE
  We performed a systematic review to determine the effect of inspiratory muscle training (IMT) on inspiratory muscle strength and endurance, exercise capacity, dyspnoea and quality of life for adolescents and adults living with cystic fibrosis.
  
  
  METHODS
  MEDLINE, EMBASE and CINAHL electronic databases were searched up to January 2008.
  
  
  METHODS
  We performed a systematic review using the methodology outlined in the Cochrane Collaboration protocol. Articles were included if: (1) participants were adolescents or adults with cystic fibrosis (> 13 years of age); (2) an IMT group was compared to a sham IMT, no intervention or other intervention group; (3) the study used a randomized controlled trial or cross-over design; and (4) it was published in English. Data were abstracted and methodological quality was assessed independently by two reviewers.
  
  
  RESULTS
  The search strategy yielded 36 articles, of which two met the inclusion criteria. Both studies used a targeted or threshold device for IMT. Meta-analyses were limited to forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC), which showed no difference in effect between the IMT group and the sham and/or control group. Individual study results were inconclusive for improvement in inspiratory muscle strength. One study demonstrated improvement in inspiratory muscle endurance.
  
  
  CONCLUSIONS
  The benefit of IMT in adolescents and adults with cystic fibrosis for outcomes of inspiratory muscle function is supported by weak evidence. Its impact on exercise capacity, dyspnoea and quality of life is not clear. Future research should investigate the characteristics of the subgroup of people with cystic fibrosis that might benefit most from IMT.
authors.affiliation: Department of Physical Therapy, University of British Columbia, Muscle Biophysics Laboratory, Vancouver, BC, Canada. darlene.reid@ubc.ca
authors.forename: W Darlene
authors.initials: WD
authors.lastname: Reid
authors.forename: E Lynne
authors.initials: EL
authors.lastname: Geddes
authors.forename: Kelly
authors.initials: K
authors.lastname: O'Brien
authors.forename: Dina
authors.initials: D
authors.lastname: Brooks
authors.forename: Jean
authors.initials: J
authors.lastname: Crowe
mesh_terms: D000293:Adolescent; D000328:Adult; D001945:Breathing Exercises; D003550:Cystic Fibrosis / Q000150:complications / Q000503:physiopathology / Q000534:rehabilitation*; D004417:Dyspnea / Q000209:etiology; D006801:Humans; D001239:Inhalation / Q000502:physiology; D007320:Inspiratory Capacity; D015201:Meta-Analysis as Topic; D053580:Muscle Strength; D011788:Quality of Life; D016032:Randomized Controlled Trials as Topic; D012132:Respiratory Muscles / Q000503:physiopathology*; D012138:Respiratory Therapy / Q000379:methods*